| 1 | use matrix_sdk::{ |
| 2 | Room, |
| 3 | event_cache::{EventCacheError, HistoryGapFillOutcome, HistoryGapStatus}, |
| 4 | }; |
| 5 | use ruma::{OwnedRoomId, OwnedTransactionId}; |
| 6 | use tokio::sync::watch; |
| 7 | |
| 8 | use super::{ |
| 9 | executor::{JoinError, JoinHandle, spawn}, |
| 10 | timeline::SessionContext, |
| 11 | }; |
| 12 | use crate::{ |
| 13 | CommandOutput, Error, ErrorKind, Event, HistoryContinuity, HistoryRepairCommand, |
| 14 | HistoryRepairPhase, HistoryRepairReport, HistoryRepairStop, RecentHistoryState, |
| 15 | transport::Responder, |
| 16 | }; |
| 17 | |
| 18 | const MAX_GAP_PAGES: u32 = 4; |
| 19 | |
| 20 | struct Running { |
| 21 | task: JoinHandle<Finished>, |
| 22 | cancel: watch::Sender<bool>, |
| 23 | responders: Vec<PendingResponder>, |
| 24 | gap_id: Option<OwnedTransactionId>, |
| 25 | closing: bool, |
| 26 | } |
| 27 | |
| 28 | struct PendingResponder { |
| 29 | responder: Responder, |
| 30 | cancel_ack: bool, |
| 31 | } |
| 32 | |
| 33 | pub(super) enum Outcome { |
| 34 | Recent(RecentHistoryState), |
| 35 | Fill(HistoryRepairReport), |
| 36 | } |
| 37 | |
| 38 | pub(super) struct Completion { |
| 39 | pub(super) outcome: Outcome, |
| 40 | /// history went into the cache, so the room timeline has to show it before anyone hears |
| 41 | pub(super) committed: bool, |
| 42 | pub(super) closing: bool, |
| 43 | pub(super) result: Result<CommandOutput, Error>, |
| 44 | responders: Vec<PendingResponder>, |
| 45 | } |
| 46 | |
| 47 | impl Completion { |
| 48 | /// the room timeline couldn't show what was committed |
| 49 | pub(super) fn unpublished(&mut self, error: Error) { |
| 50 | match &mut self.outcome { |
| 51 | Outcome::Recent(state) => *state = RecentHistoryState::Failed(error.message.clone()), |
| 52 | Outcome::Fill(report) => { |
| 53 | report.phase = HistoryRepairPhase::Paused; |
| 54 | report.failure = Some(error.clone()); |
| 55 | } |
| 56 | } |
| 57 | self.result = Err(error); |
| 58 | } |
| 59 | |
| 60 | pub(super) fn resolve( |
| 61 | self, |
| 62 | result: Result<CommandOutput, Error>, |
| 63 | cancellation: Result<(), Error>, |
| 64 | ) { |
| 65 | for responder in self.responders { |
| 66 | if responder.cancel_ack { |
| 67 | responder.responder.done(cancellation.clone()); |
| 68 | } else { |
| 69 | responder.responder.send(result.clone()); |
| 70 | } |
| 71 | } |
| 72 | } |
| 73 | } |
| 74 | |
| 75 | enum Stopped { |
| 76 | Done, |
| 77 | Cancelled, |
| 78 | Failed(Error), |
| 79 | } |
| 80 | |
| 81 | struct Finished { |
| 82 | stopped: Stopped, |
| 83 | committed: bool, |
| 84 | report: Option<HistoryRepairReport>, |
| 85 | } |
| 86 | |
| 87 | pub(super) struct RepairController { |
| 88 | room: Room, |
| 89 | context: SessionContext, |
| 90 | running: Option<Running>, |
| 91 | } |
| 92 | |
| 93 | impl RepairController { |
| 94 | pub(super) fn new(room: Room, context: SessionContext) -> Self { |
| 95 | Self { |
| 96 | room, |
| 97 | context, |
| 98 | running: None, |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | pub(super) fn is_running(&self) -> bool { |
| 103 | self.running.is_some() |
| 104 | } |
| 105 | |
| 106 | /// a room with retained events already shows the live end, and a limited sync has put its |
| 107 | /// own gap there, so only an empty room walks back from the live end. otherwise the newest |
| 108 | /// gap gets one page, so a limited sync that skipped nothing leaves no gap behind |
| 109 | pub(super) async fn start_recent(&mut self) { |
| 110 | let retained = async { |
| 111 | let (cache, _handles) = self.room.event_cache().await?; |
| 112 | if !cache.has_retained_events().await? { |
| 113 | return Ok(None); |
| 114 | } |
| 115 | let gaps = cache.history_gaps().await?; |
| 116 | Ok::<_, EventCacheError>(Some(gaps.into_iter().rev().find(|gap| { |
| 117 | matches!( |
| 118 | gap.status, |
| 119 | HistoryGapStatus::Idle | HistoryGapStatus::Failed { .. } |
| 120 | ) |
| 121 | }))) |
| 122 | } |
| 123 | .await; |
| 124 | match retained { |
| 125 | Ok(Some(Some(gap))) => self.start_gap_fill(gap.id, None, 1, false).await, |
| 126 | Ok(Some(None)) => {} |
| 127 | Ok(None) | Err(_) => self.start_recent_with(None).await, |
| 128 | } |
| 129 | } |
| 130 | |
| 131 | pub(super) async fn execute(&mut self, command: HistoryRepairCommand, reply: Responder) { |
| 132 | match command { |
| 133 | HistoryRepairCommand::Cancel { .. } => { |
| 134 | if let Some(running) = self.running.as_mut() { |
| 135 | running.responders.push(PendingResponder { |
| 136 | responder: reply, |
| 137 | cancel_ack: true, |
| 138 | }); |
| 139 | running.cancel.send_replace(true); |
| 140 | } else { |
| 141 | reply.done(Ok(())); |
| 142 | } |
| 143 | } |
| 144 | HistoryRepairCommand::RetryRecent { .. } => self.start_recent_with(Some(reply)).await, |
| 145 | HistoryRepairCommand::FillGap { gap_id, .. } => { |
| 146 | self.start_gap_fill(gap_id, Some(reply), MAX_GAP_PAGES, true) |
| 147 | .await; |
| 148 | } |
| 149 | } |
| 150 | } |
| 151 | |
| 152 | async fn start_recent_with(&mut self, responder: Option<Responder>) { |
| 153 | if let Some(running) = &mut self.running { |
| 154 | if let Some(responder) = responder { |
| 155 | if running.gap_id.is_none() { |
| 156 | running.responders.push(PendingResponder { |
| 157 | responder, |
| 158 | cancel_ack: false, |
| 159 | }); |
| 160 | } else { |
| 161 | responder.done(Err(room_busy())); |
| 162 | } |
| 163 | } |
| 164 | return; |
| 165 | } |
| 166 | let event = Event::RecentHistoryChanged { |
| 167 | room_id: self.room.room_id().to_owned(), |
| 168 | state: RecentHistoryState::Loading, |
| 169 | }; |
| 170 | if self.context.events.send(event).await.is_err() { |
| 171 | if let Some(responder) = responder { |
| 172 | responder.done(Err(Error::interrupted())); |
| 173 | } |
| 174 | return; |
| 175 | } |
| 176 | let (cancel, receiver) = watch::channel(false); |
| 177 | let room = self.room.clone(); |
| 178 | let task = spawn(async move { load_recent(room, receiver).await }); |
| 179 | self.running = Some(Running { |
| 180 | task, |
| 181 | cancel, |
| 182 | responders: responder |
| 183 | .map(|responder| PendingResponder { |
| 184 | responder, |
| 185 | cancel_ack: false, |
| 186 | }) |
| 187 | .into_iter() |
| 188 | .collect(), |
| 189 | gap_id: None, |
| 190 | closing: false, |
| 191 | }); |
| 192 | } |
| 193 | |
| 194 | async fn start_gap_fill( |
| 195 | &mut self, |
| 196 | gap_id: OwnedTransactionId, |
| 197 | responder: Option<Responder>, |
| 198 | pages: u32, |
| 199 | spend_budget: bool, |
| 200 | ) { |
| 201 | if self.is_running() { |
| 202 | if let Some(responder) = responder { |
| 203 | responder.done(Err(room_busy())); |
| 204 | } |
| 205 | return; |
| 206 | } |
| 207 | let room = self.room.clone(); |
| 208 | let progress = report(self.room.room_id().to_owned(), gap_id.clone()); |
| 209 | if self |
| 210 | .context |
| 211 | .events |
| 212 | .send(Event::HistoryRepairChanged(progress.clone())) |
| 213 | .await |
| 214 | .is_err() |
| 215 | { |
| 216 | if let Some(responder) = responder { |
| 217 | responder.done(Err(Error::interrupted())); |
| 218 | } |
| 219 | return; |
| 220 | } |
| 221 | let (cancel, receiver) = watch::channel(false); |
| 222 | let task = |
| 223 | spawn(async move { fill_gap(room, progress, receiver, pages, spend_budget).await }); |
| 224 | self.running = Some(Running { |
| 225 | task, |
| 226 | cancel, |
| 227 | responders: responder |
| 228 | .map(|responder| PendingResponder { |
| 229 | responder, |
| 230 | cancel_ack: false, |
| 231 | }) |
| 232 | .into_iter() |
| 233 | .collect(), |
| 234 | gap_id: Some(gap_id), |
| 235 | closing: false, |
| 236 | }); |
| 237 | } |
| 238 | |
| 239 | pub(super) async fn next_completion(&mut self) -> Option<Completion> { |
| 240 | let running = self.running.as_mut()?; |
| 241 | let result = (&mut running.task).await; |
| 242 | Some(self.finish_task(result)) |
| 243 | } |
| 244 | |
| 245 | pub(super) async fn shutdown(&mut self) -> Option<Completion> { |
| 246 | let running = self.running.as_mut()?; |
| 247 | running.closing = true; |
| 248 | running.cancel.send_replace(true); |
| 249 | let result = (&mut running.task).await; |
| 250 | Some(self.finish_task(result)) |
| 251 | } |
| 252 | |
| 253 | fn finish_task(&mut self, result: Result<Finished, JoinError>) -> Completion { |
| 254 | let running = self.running.take().expect("repair task exists"); |
| 255 | let finished = result.unwrap_or(Finished { |
| 256 | stopped: Stopped::Failed(Error::interrupted()), |
| 257 | committed: false, |
| 258 | report: None, |
| 259 | }); |
| 260 | let result = match &finished.stopped { |
| 261 | Stopped::Done => Ok(CommandOutput::Done), |
| 262 | Stopped::Cancelled => Err(Error::interrupted()), |
| 263 | Stopped::Failed(error) => Err(error.clone()), |
| 264 | }; |
| 265 | let outcome = match running.gap_id { |
| 266 | None => Outcome::Recent(match finished.stopped { |
| 267 | _ if running.closing => RecentHistoryState::Idle, |
| 268 | Stopped::Done => RecentHistoryState::Loaded, |
| 269 | Stopped::Cancelled => RecentHistoryState::Cancelled, |
| 270 | Stopped::Failed(error) => RecentHistoryState::Failed(error.message), |
| 271 | }), |
| 272 | Some(gap_id) => { |
| 273 | let mut report = finished |
| 274 | .report |
| 275 | .unwrap_or_else(|| report(self.room.room_id().to_owned(), gap_id)); |
| 276 | match finished.stopped { |
| 277 | Stopped::Done => {} |
| 278 | Stopped::Cancelled => report.stop = Some(HistoryRepairStop::Cancelled), |
| 279 | Stopped::Failed(error) => report.failure = Some(error), |
| 280 | } |
| 281 | report.phase = if report.stop.is_none() && report.failure.is_none() { |
| 282 | HistoryRepairPhase::Ready |
| 283 | } else { |
| 284 | HistoryRepairPhase::Paused |
| 285 | }; |
| 286 | Outcome::Fill(report) |
| 287 | } |
| 288 | }; |
| 289 | Completion { |
| 290 | outcome, |
| 291 | committed: finished.committed, |
| 292 | closing: running.closing, |
| 293 | result, |
| 294 | responders: running.responders, |
| 295 | } |
| 296 | } |
| 297 | } |
| 298 | |
| 299 | async fn load_recent(room: Room, mut cancel: watch::Receiver<bool>) -> Finished { |
| 300 | let outcome = tokio::select! { |
| 301 | biased; |
| 302 | _ = cancel.changed() => None, |
| 303 | result = async { |
| 304 | let (cache, _handles) = room.event_cache().await?; |
| 305 | cache.load_recent_history().await |
| 306 | } => Some(result), |
| 307 | }; |
| 308 | let stopped = match outcome { |
| 309 | None => Stopped::Cancelled, |
| 310 | Some(Ok(_)) => Stopped::Done, |
| 311 | Some(Err(error)) => Stopped::Failed(cache_error(error)), |
| 312 | }; |
| 313 | Finished { |
| 314 | committed: matches!(stopped, Stopped::Done), |
| 315 | stopped, |
| 316 | report: None, |
| 317 | } |
| 318 | } |
| 319 | |
| 320 | async fn fill_gap( |
| 321 | room: Room, |
| 322 | mut report: HistoryRepairReport, |
| 323 | mut cancel: watch::Receiver<bool>, |
| 324 | pages: u32, |
| 325 | spend_budget: bool, |
| 326 | ) -> Finished { |
| 327 | let mut committed = false; |
| 328 | let stopped = async { |
| 329 | let (cache, _handles) = room.event_cache().await.map_err(cache_error)?; |
| 330 | for _ in 0..pages { |
| 331 | let next = tokio::select! { |
| 332 | biased; |
| 333 | _ = cancel.changed() => return Ok(Stopped::Cancelled), |
| 334 | result = cache.fill_history_gap_once(report.gap_id.clone()) => match result { |
| 335 | Ok(next) => next, |
| 336 | Err(error) => { |
| 337 | committed |= matches!(error, EventCacheError::PaginationError(_)); |
| 338 | return Err(cache_error(error)); |
| 339 | } |
| 340 | } |
| 341 | }; |
| 342 | let (gap, events) = match next { |
| 343 | HistoryGapFillOutcome::NotFound => { |
| 344 | return Err(Error::new( |
| 345 | ErrorKind::EventNotFound, |
| 346 | "history gap was not found", |
| 347 | )); |
| 348 | } |
| 349 | HistoryGapFillOutcome::Busy => return Err(room_busy()), |
| 350 | HistoryGapFillOutcome::Updated { gap, events } => (gap, events), |
| 351 | }; |
| 352 | // the sdk answers an already unavailable gap without asking the server, and a joined |
| 353 | // one with NotFound. an empty first page that hits the end looks the same, uncounted |
| 354 | let settled_before = |
| 355 | report.pages == 0 && events == 0 && gap.status == HistoryGapStatus::Unavailable; |
| 356 | if !settled_before { |
| 357 | report.pages += 1; |
| 358 | committed = true; |
| 359 | } |
| 360 | report.events = report |
| 361 | .events |
| 362 | .saturating_add(u32::try_from(events).unwrap_or(u32::MAX)); |
| 363 | match gap.status { |
| 364 | HistoryGapStatus::Joined => { |
| 365 | report.continuity = HistoryContinuity::Verified; |
| 366 | return Ok(Stopped::Done); |
| 367 | } |
| 368 | HistoryGapStatus::Unavailable => { |
| 369 | report.continuity = HistoryContinuity::AccessibleStart; |
| 370 | report.stop = Some(HistoryRepairStop::HistoryUnavailable); |
| 371 | return Ok(Stopped::Done); |
| 372 | } |
| 373 | HistoryGapStatus::Paused => { |
| 374 | report.stop = Some(HistoryRepairStop::CursorStalled); |
| 375 | return Ok(Stopped::Done); |
| 376 | } |
| 377 | HistoryGapStatus::Failed { message } => { |
| 378 | return Err(Error::new(ErrorKind::Network, message)); |
| 379 | } |
| 380 | HistoryGapStatus::Idle | HistoryGapStatus::BudgetSpent => {} |
| 381 | } |
| 382 | } |
| 383 | report.stop = Some(HistoryRepairStop::Budget); |
| 384 | if spend_budget { |
| 385 | if let Err(error) = cache.spend_history_budget(report.gap_id.clone()).await { |
| 386 | tracing::debug!(%error, "marking a history gap's spent budget failed"); |
| 387 | } |
| 388 | committed = true; |
| 389 | } |
| 390 | Ok(Stopped::Done) |
| 391 | } |
| 392 | .await |
| 393 | .unwrap_or_else(Stopped::Failed); |
| 394 | Finished { |
| 395 | stopped, |
| 396 | committed, |
| 397 | report: Some(report), |
| 398 | } |
| 399 | } |
| 400 | |
| 401 | fn report(room_id: OwnedRoomId, gap_id: OwnedTransactionId) -> HistoryRepairReport { |
| 402 | HistoryRepairReport { |
| 403 | room_id, |
| 404 | gap_id, |
| 405 | pages: 0, |
| 406 | events: 0, |
| 407 | phase: HistoryRepairPhase::Bridging, |
| 408 | continuity: HistoryContinuity::Unresolved, |
| 409 | stop: None, |
| 410 | failure: None, |
| 411 | } |
| 412 | } |
| 413 | |
| 414 | fn cache_error(source: EventCacheError) -> Error { |
| 415 | let kind = match &source { |
| 416 | EventCacheError::PaginationError(error) => crate::error::classify_sdk_error(error), |
| 417 | EventCacheError::InitialPaginationError(_) => ErrorKind::Network, |
| 418 | EventCacheError::RoomNotFound { .. } => ErrorKind::RoomUnknown, |
| 419 | EventCacheError::ClientDropped => ErrorKind::Interrupted, |
| 420 | _ => ErrorKind::Store, |
| 421 | }; |
| 422 | Error::with_source(kind, "room history operation failed", source) |
| 423 | } |
| 424 | |
| 425 | fn room_busy() -> Error { |
| 426 | Error::new( |
| 427 | ErrorKind::RoomBusy, |
| 428 | "room history operation is already running", |
| 429 | ) |
| 430 | } |